I bought my F250 with the camper package before I got a TC. It took about $100 going from 2" rear blocks to 4" to make it better than a stock F350 since it already had bags and an extra leaf in the front. F250 and F350 are almost the same exact trucks, same axles and such, not sure about dogs and chebys.
I'm pretty sure a lot of guys get into campers AFTER they already have a truck and learn that way. If I bought new, I would purchase a F350, I got lucky having the camper package with overloads on my F250.